JPS6177231A - Manufacture of cathode-ray tube - Google Patents

Abstract

PURPOSE:To suppress generation of tube inside discharge while reducing generation of electric field emission electrons by generating the discharge plasma around the electron guns in an argon atmosphere. CONSTITUTION:The assembled electron guns are mounted inside a glass bulb of a cathode-ray tube while being evacuated followed by sealing argon for performing discharge. In the discharge plasma in argon, argon molecules are excited while colliding with electrodes of an electron gun but argon itself is chemically inert so as to produce no compound with an electrode material thus driving out impurities on the electrode surface and cleaning the electrode surface. The treated cathode-ray tube proper is thereafter evacuated until the bulb inside restores a vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of manufacturing a cathode ray tube for suppressing deviation of electron beam trajectory due to charging of the inner surface of a glass bulb.

[Conventional technology] FIG. 5 is a schematic diagram showing the structure of a general cathode ray tube.

In the figure, (1) is a low voltage electrode (2a), (2b)
, (2c), an electron gun consisting of a focusing electrode (3) and an anode (4), (5) a glass bulb that houses this electron gun (1) and whose interior is kept in a high vacuum, (6) is a conductive film coated on the inner surface of this glass bulb (5), (7) is a high voltage power supply connected to this conductive film (6), and (8) is the low voltage electrode (2a), (2b), ( 2c) and a control power source for supplying voltage to the focusing electrode (3), (8
) indicates field emission electrons from the high-field electrode portion, and (11) indicates the cathode ray tube body.

Next, the operation will be explained. Low voltage electrode (2a).

Electron beams are generated in parts (2b) and (2c), and their intensity is controlled. A certain positive voltage is applied to the focusing electrode (3), and a high voltage of W polarity is applied to the anode (4) to focus the electron beam.

At this time, field emission electrons (9) as shown in FIG. 5 are generated from the ends of the focusing electrode (3) and the low voltage electrode (2c), where a high electric field of negative polarity is generated. This field emission electron (9)
When the amount increases, intratubular discharge is induced. In order to suppress this intraluminal discharge, it is necessary to suppress the generation of field emission electrons (9). It is believed that field emission electrons (9) are likely to be generated from minute protrusions or impurities on the electrode surface.

[Problems to be Solved by the Invention] By the way, as shown in FIG. 4, the conventional method of manufacturing a cathode ray tube involves assembling an electron gun.The first step in assembling the electron gun is to mount the assembled electron gun into the glass bulb of the cathode ray tube. It consists of step B, step C of vacuum evacuation of the glass bulb, step F of seasoning by applying high voltage, and step G of adjusting and checking the operation. Since no treatment has been applied to sufficiently clean the tube, it has been difficult to suppress intraluminal discharge.

The present invention has been made to overcome the above-mentioned conventional drawbacks, and an object of the present invention is to provide a method for manufacturing a cathode ray tube in which the generation of field emission electrons is reduced and the occurrence of discharge within the tube is suppressed.

[Means for Solving the Problem 1] This invention first sets the assembled electron gun inside the glass bulb of a cathode ray tube and performs evacuation, then introduces argon into the glass bulb and evacuates the argon atmosphere. In 8, the electrode surface of the electron gun is treated by generating discharge plasma around the electron gun, and then the inside of the glass bulb is evacuated to vacuum again to seal the electron gun inside the glass bulb. shall be.

[Operation] In this invention, excited argon molecules collide with the electrode of the electron gun by generating discharge plasma around the electron gun, but since argon itself is chemically inert, the electrode material No compounds are formed between
Impurities on the electrode surface E are expelled to clean the electrode surface.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of steps in a method for manufacturing a cathode ray tube according to the present invention. Compared to the conventional device shown in FIG. 4, a new process has been added in which after the glass bulb is evacuated, argon is filled in and discharged, and a process E is then performed where the vacuum is evacuated again.

FIG. 2 shows an example of the process of performing discharge. In the figure, (12) is the cathode ray tube body (
A contactor (11) is used to bring the high voltage terminal into contact with a high voltage line, and (13) is a high voltage power source. By doing this, a high voltage is applied to the cathode ray tube body (11) through the electron gun (
It can be applied to part 1). The applied voltage may be direct current, alternating current, or pulsed.

When a high voltage is applied to the electron gun (1), the connection between the anode (4) and the focusing electrode (3), and between the anode (4) and the low voltage electrodes (2a), (2b), (2c) via argon A discharge occurs between the two, producing discharge plasma. In the discharge plasma in argon, argon molecules are excited and the electron gun (1
), but since argon itself is chemically inert, it does not form compounds with the electrode material.
Cleans the electrode surface by expelling impurities on the electrode surface. This reduces impurities that cause the generation of field emission electrons (8) and suppresses the generation of field emission electrons (9), making it possible to manufacture highly reliable cathode ray tubes with less internal discharge. .

After the cathode ray tube body (!l) processed in this manner, the inside of the glass bulb (5) is evacuated again to vacuum, and the electron gun (1) is sealed in the glass bulb (5) as it is.

In the above embodiment, high voltage was applied to the anode (4), but the anode (4) was grounded and the converging electrode (3) or low voltage electrode (2a), (
A high voltage may be applied to 2b) and (2c).

FIG. 3 shows another embodiment of the invention.

In this embodiment, a coil (14) is disposed outside the glass bulb close to the electron gun (1), and a high frequency current is supplied to this coil (14) from a high frequency power source (15) to discharge around the electrode. It is designed to generate plasma.

In the case of Fig. 3, a high frequency magnetic field is applied to the electron gun (1), but instead of this, for example, a high frequency electric field from parallel plate electrodes or a high frequency electromagnetic field from a traveling wave tube may be applied. A similar discharge plasma can also be generated.

[Effects of the Invention] As described in J- below, according to the present invention, the electrode surface of the electron gun is ablated by the discharge plasma, and impurities that cause field emission electrons are reduced.

A highly reliable method for manufacturing a cathode ray tube with less internal discharge can be provided.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the manufacturing process of a cathode ray tube according to the present invention;
Figure 2 is a diagram showing an example of the discharge process, Figure 3 is a diagram showing another example of the discharge process, Figure 4 is a diagram showing the conventional cathode ray tube manufacturing process, and Figure 5 is a general diagram. 1 is a schematic cross-sectional view showing the structure of a typical cathode ray tube. (1)...Electron gun, (5)...Glass bulb, (1
3)...High voltage power supply, (14)...Coil, (15)
...High frequency power supply. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (3)

[Claims] (1) After setting the assembled electron gun inside the glass bulb of the cathode ray tube and evacuation, argon is introduced into the glass bulb, and discharge plasma is generated around the electron gun in this argon atmosphere. 1. A method for manufacturing a cathode ray tube, characterized in that the electrode surface of the electron gun is treated by generating the electron gun, and then the inside of the glass bulb is evacuated again to vacuum, and the electron gun is sealed within the glass bulb. (2) A method for manufacturing a cathode ray tube according to claim 1, in which discharge plasma is generated by applying a high voltage to an anode, a focusing electrode, or a low-voltage electrode of an electron gun. (3) The method for manufacturing a cathode ray tube according to claim 1, wherein discharge plasma is generated by applying a high frequency magnetic field or a high frequency electric field to the electron gun from outside the glass bulb.